International Journal of Mycobacteriology最新文献

Background: The objective is to assess lung compliance and identify the optimal positive end-expiratory pressure (PEEP) levels in patients with tuberculosis-associated Acute Respiratory Distress Syndrome (TB-ARDS) compared to non-TB-ARDS patients.

Methods: This observational case-control study utilized electrical impedance tomography to evaluate lung mechanics in 20 TB-ARDS and 20 non-TB-ARDS patients. Participants underwent PEEP titration from 23 to 5 cm H2O in 2 cm H2O decrements. Lung compliance and the rates of hyperdistention and collapse were assessed at each PEEP level.

Results: Delta impedance values showed higher amounts in a PEEP range of 11-17 cm H2O and in patients with TB-ARDS (P > 0.05). In addition, both hyperdistention and collapse rates were nonsignificantly higher in TB-ARDS patients (P > 0.05), and the compromised levels of hyperdistention and collapse rates were at 15-17 cm H2O, indicating the most favorable PEEP level.

Conclusions: The observed patterns of hyperdistention and collapse rates across various PEEP levels provide valuable insights into the susceptibility of TB-ARDS patients to barotrauma. Notably, the identified optimal PEEP range between 15 and 17 cm H2O may guide ventilator management strategies in mitigating both hyperdistention and collapse; nonetheless, due to the high variability of lung compliances within groups, we strongly recommend individualized consideration for tailored respiratory support and evaluation.

Bacteria other than Mycobacterium tuberculosis and Mycobacterium leprae are known as nontuberculous mycobacteria (NTM), and the frequency of clinically symptomatic forms is increasing day by day. Mycobacterium fortuitum, a rapidly reproducing NTM, causes various clinical signs such as skin soft-tissue infection, surgical site infection, and disseminated infection in immunosuppressed patients. Although progress can be made in terms of diagnosis when growth is detected in culture, it is quite difficult to distinguish between infection and contamination. There is no place for antituberculosis treatment in the treatment of M. fortuitum. Antibiotics such as quinolones, trimethoprim-sulfamethoxazole, linezolid, doxycycline, clarithromycin, azithromycin, imipenem, tigecycline, linezolid, and amikacin are recommended at least in dual combination therapy. In this case presentation, the diagnosis and treatment of a 2-year skin soft-tissue infection with M. fortuitum growth in culture will be discussed.

To systematize published laboratory methods to inactivate Mycobacterium tuberculosis (MTB) and to describe their effectiveness. We carried out a review of the scientific literature to identify the publications that reported methods for the inactivation of MTB, according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses recommendations. The search addressed inactivation methodologies used in Public health laboratories for the treatment of biological material and only included studies reporting the efficacy of the method. The database used were PubMed (National Library of Medicine) and LILACS (Latin American and Caribbean Literature in Health Sciences). We evaluated the quality of the studies with the JBI (Joanna Briggs Institute) Critical Instrument Appraisal Checklist. We included 14 publications meeting the established inclusion and exclusion criteria. These 14 studies actually described a total of 35 inactivation methods. Most of them combined heat treatment with some chemical or enzymatic agent, and there were very few applying a single strategy. Twenty-four (68.57%) methods demonstrated significant efficacy in inactivating MTB. The systematic review identified 35 methods of inactivation of MTB, published in 14 studies. Most of the methods combined physical treatment techniques, especially heat, with chemical and/or enzymatic treatment techniques, obtaining mostly good results in preventing the reproduction of the microorganism. PROSPERO (International Prospective Register of Ongoing Systematic Reviews) (Code CRD42024503621).

Background: Mycobacterium abscessus complex (MABSc) causes chronic infection in patients with concomitant structural changes in the respiratory tract, which is especially important for patients with cystic fibrosis. To isolate an MABSc culture from clinical material, a variety of nutrient media are used. For species determination of microorganisms isolated on these media, additional identification methods are used, for example, polymerase chain reaction, sequencing, or mass spectrometry. The latter method is relatively easy to implement but requires improvement, due to the identification inaccuracy of nontuberculosis mycobacterias in general. Consequently, a set of nutrient media may be important for subsequent identification by mass spectrometry.

Methods: The study was conducted on 64 strains of MABSc representatives: 56 strains were obtained from patients with cystic fibrosis and 8 strains from patients with pulmonary pathology unrelated to cystic fibrosis. The obtained MABSc strains were transplanted to the universal chromogenic medium and the selective medium for the Burkholderia cepacia complex (BCC) isolation. Species identification was carried out by mass spectrometry based on matrix-activated laser time-of-flight desorption/ionization (MALDI-ToF MS). Microbial identification is based on a comparison of the obtained mass spectra with reference spectra from the database. Microorganisms were identified based on the coincidence degree (Score value). Sample preparation for microbial identification by mass spectrometry was carried out by an extended direct application method. Fragments of the rpoB and hsp65 genes with lengths of 752 bp and 441 bp, respectively, were used as molecular markers for subspecific identification of MABSc strains.

Results: A comparison of the peaks obtained after mass spectrometry of MABSc strains isolated on the studied nutrient media showed significant differences between these indicators selective medium for the BCC isolation with the supplement of iron polymaltose hydroxide (III) and universal chromogenic medium (P < 0.001) and selective medium for the BCC isolation with universal chromogenic medium (P < 0.001). Twenty-five strains of MABSc representatives were sequenced: results of subspecies determination in strains isolated on the universal chromogenic medium coincided with the results sequencing in 13 (86.6%) strains out of 15.

Conclusion: MALDI-ToF mass spectrometry allows microbial identification in a short time and with minimal cost, but it does not yet allow the proper identification of the subspecies of certain microbial groups, such as MABSc. Cultivation methods need optimization and new approaches to the extraction process of the bacterial protein fraction.

In this review, two cases of testicular tuberculosis (TB) are presented, and another 58 cases published in PubMed between January 1, 2012, and July 31, 2023, are reviewed. Testicular TB remains a disease mainly of the developing world, with one notable exception - the infections caused as a result of Bacillus Calmette-Guérin infusion immunotherapy for bladder cancer. Its clinical course is subacute; however, it might get disseminated and become life-threatening; therefore, prompt diagnosis is very important. The diagnosis can be quite challenging, and testicular tissue is the sample with the highest diagnostic yield, either for microbiological or histopathological diagnosis. On the other hand, its treatment follows the standard guidelines for TB treatment; however, the avoidance of an unnecessary orchiectomy is important.

Background: Tuberculosis (TB) remains a significant global health concern, with extrapulmonary manifestations, including central nervous system involvement, posing substantial morbidity and mortality. While medical treatment with anti-TB drugs is the mainstay of therapy, certain TB-related cerebral complications, such as hydrocephalus, abscesses, and large symptomatic tuberculomas, may require surgical intervention. This study aimed to evaluate the outcomes of surgical management in patients with TB-related cerebral disorders.

Methods: A retrospective analysis was conducted on 24 patients who underwent surgical intervention for TB-related cerebral disorders, including tuberculomas, hydrocephalus, and abscesses, at a tertiary care center between 2005 and December 2020. Demographic data, clinical presentations, radiological findings, surgical techniques, and treatment outcomes were analyzed.

Results: The study cohort had a mean age of 35.8 ± 13.6 years, and the majority (62.5%) were male. Underlying immunodeficiency, primarily HIV infection, was present in 75% of the patients. The most common presenting symptoms were headache (83.3%), focal neurological deficits (75%), and altered mental status (54.2%). Radiological findings revealed 13 (54.2%) tuberculomas, 8 (33.3%) instances of hydrocephalus, and 3 (12.5%) abscesses. VP shunt inserted in 8 (33.3%) cases. Microscopic craniotomy performed in 7 (29.16%) cases. Aspiration through burr hole was done in 3 (12.5%) cases and stereotactic biopsy was performed in 6 (25%) cases. After 12 months of follow-up, favorable outcome achieved in 18 cases (75%) and the mortality occurred in 2 patients (8.3%). Surgical interventions included lesion resection (n = 10), stereotactic biopsy (n = 7), and ventriculoperitoneal (VP) shunt placement (n = 7). At 12-month follow-up, 18 (75%) patients had a favorable outcome, defined as clinical improvement or stabilization. Unfavorable outcomes were observed in 6 (25%) patients, including 2 deaths.

Conclusion: Surgical management, in conjunction with appropriate anti-TB medical therapy, may be a valuable component of the comprehensive treatment approach for select patients with TB-related cerebral disorders. The favorable outcome rate observed in this study suggests that timely and tailored surgical intervention can contribute to improved patient outcomes. However, larger, prospective, multicenter studies are needed to further elucidate the role and long-term efficacy of surgical management in this patient population.

Background: Drug-resistant tuberculosis (DR-TB) poses a major global challenge to public health and therapeutics. It is an emerging global concern associated with increased morbidity and mortality mostly seen in the low- and middle-income countries. Molecular techniques are highly sensitive and offer timely and accurate results for TB drug resistance testing, thereby positively influencing patient management plan.

Methods: The study was carried out at the National Tuberculosis Reference Laboratory (NTRL) in Kenya in the period between January and October 2022. A total of 243 Mycobacterium tuberculosis (M.tb) clinical isolates were included in the study. These isolates comprised of 50 isolates with mutations in rpoB, 51 isolates with katG mutations, 51 isolates with mutations in inhA, and 91 M.tb isolates lacking mutations in these genes based on Genotype MTBDRplus results. DNA from the isolates was extracted using the FluoroLyse extraction kit. Real-time polymerase chain reaction targeting the rpoB, InhA, and katG genes was performed using the FluoroType MTBDR amplification mix. Isolates with discordant results between Genotype MTBDRplus and FluoroCycler® MTBDR assays underwent targeted sequencing for the respective genes, then, sequences were analyzed for mutations using Geneious version 11.0 software.

Results: The sensitivity of the Fluorocycler XT MTBDR assay for the detection of mutations that confer drug resistance was 86% (95% confidence interval [CI] 73.0-94.0) for rpoB, 96% (95% CI 87-100) for katG and 92% (95% CI 81-98) for inhA. The assay's specificity was 97% (95% CI 93-99) for rpoB, 98% (95% CI 96-100) for katG, and 97% (95% CI 93-99) for inhA.

Conclusion: The diagnostic accuracy of FluoroType MTBDR for the detection of mutations conferring resistance to rifampicin and isoniazid was high compared with that of Genotype MTBDRplus and demonstrates its suitability as a replacement assay for Genotype MTBDRplus.

Background: Extrapulmonary tuberculosis (EPTB) makes for 25% of all instances of tuberculosis (TB) patients. The enigmatic clinical presentation of EPTB makes identification difficult since it simulates other chronic conditions such as neoplastic and inflammatory disorders and could culminate in treatment that is either insufficient or not required. For an affirmative and confirmed diagnosis, a substantial level of suspicion is imperative. The paucibacillary feature of EPTB makes diagnosis extremely difficult and necessitates the use of many diagnostic methods to arrive at a precise diagnosis. In December 2010, the World Health Organization recommended using GeneXpert/cartridge-based nucleic acid amplification test (CBNAAT) for the initial assessment of suspected cases of EPTB. Furthermore, fine-needle aspiration cytology (FNAC), Ziehl-Neelsen (ZN) stain, and the CBNAAT have to be utilized to exclude other possible origins of granulomatous inflammation. The goal of the current investigation is to comprehend how FNAC and ZN stains relate to CBNAAT and their diagnostic value.

Methods: The evaluation included all suspected instances of tubercular lymphadenopathy, and adequate aspirates were obtained from the site of the enlarged cervical lymph nodes. Smears were made following FNAC and stained with ZN stain as well as hematoxylin and eosin stain. Simultaneously, CBNAAT and culture evaluations were conducted on the same aspirates. This cross-sectional study took place at a tertiary care center and encompassed 200 individuals with clinical manifestations of EPTB.

Results: There were 200 cases of suspected tubercular lymphadenitis (TBLN). According to the FNAC results, TBLN was detected in 71 (47.6%) of these 200 cases, followed by necrotizing lymphadenitis in 56 (37.5%), chronic caseating granulomatous lymphadenitis in 47 (31.5%), and reactive lymphadenitis in 26 (17.4%). They were correlated with CBNAAT results, which showed that all instances of tuberculous lymphadenitis, 85.71% of cases of necrotizing lymphadenitis, 55.32% of cases of chronic caseating granulomatous lymphadenitis, and 2 (7.69%) cases of reactive lymphadenitis were CBNAAT positive.

Conclusion: CBNAAT should be utilized with FNAC and ZN staining to diagnose EPTB. The CBNAAT assay demonstrated a significant advantage in the identification of previously unidentified FNAC patients. Despite being a simple diagnostic tool, FNAC has a lower specificity and significantly lower precision than CBNAAT in correctly identifying cases of EPTB because it exhibits similar cytomorphological characteristics with lesions that are not associated with TB.

Background: Tuberculosis (TB), a global infectious threat, has seen a concerning rise in aminoglycoside-resistant Mycobacterium tuberculosis (M.tb) strains. The potential role of capsule proteins remains largely unexplored. This layer acts as the primary barrier for tubercle bacilli, attempting to infiltrate host cells and subsequent disease development.

Methods: The study aims to bridge this gap by investigating the differentially expressed capsule proteins in aminoglycoside-resistant M.tb clinical isolates compared with drug-sensitive isolates employing two-dimensional gel electrophoresis, mass spectrometry, and bioinformatic approaches.

Results: We identified eight proteins that exhibited significant upregulation in aminoglycoside-resistant isolates. Protein Rv3029c and Rv2110c were associated with intermediary metabolism and respiration; Rv2462c with cell wall and cell processes; Rv3804c with lipid metabolism; Rv2416c and Rv2623 with virulence and detoxification/adaptation; Rv0020c with regulatory functions; and Rv0639 with information pathways. Notably, the Group-based Prediction System for Prokaryotic Ubiquitin-like Protein (GPS-PUP) algorithm identified potential pupylation sites within all proteins except Rv3804c. Interactome analysis using the STRING 12.0 database revealed potential interactive partners for these proteins, suggesting their involvement in aminoglycoside resistance. Molecular docking studies revealed suitable binding between amikacin and kanamycin drugs with Rv2462c, Rv3804c, and Rv2623 proteins.

Conclusion: As a result, our findings illustrate the multifaceted nature of aminoglycoside resistance in M.tb and the importance of understanding how capsule proteins play a role in counteracting drug efficacy. Identifying the role of these proteins in drug resistance is crucial for developing more effective treatments and diagnostics for TB.

Background: Mycobacterium welchii (Mycobacterium w) vaccine was one of the many strategies used to both treat and prevent coronavirus disease 2019 (COVID-19) infection. We report the results of a retrospective analysis of 15 cases with vaccine-site granulomas after administration of prophylactic Mycobacterium w vaccine as part of a trial for COVID-19 and our experience in managing those cases.

Methods: This was a retrospective analysis of 15 patients with vaccine-site granulomas who were given the vaccine as a prophylactic measure as part of a trial with informed consent.

Results: The mean average age of cases was 37 and the male-to-female ratio was 1:0.87. All of the patients developed erythematous tender nodules over the injection sites within a month of receiving the inoculations. Mycobacterial cultures and cartridge-based nucleic acid amplification tests yielded negative results. Skin biopsy revealed granulomatous dermatitis with acid-fast bacilli positivity. A diagnosis of noninfective granulomatous dermatitis was made. Treatment started with analgesics and anti-inflammatory agents. Systemic antibiotics were required in 9/15 patients. Patients are being followed up with no reported recurrence till date.

Conclusion: The possibility of injection-site granuloma should be taken into the risk-benefit analysis for the administration of Mycobacterium w vaccine and the patients should be counseled as such. Patients with persistent ulceration respond to combinations of doxycycline, ofloxacin, and clarithromycin.